Radio frequency module and communication device

ABSTRACT

A radio frequency module includes: a module board that includes a first principal surface and a second principal surface on opposite sides of the module board; a power amplifier; and a first circuit component. The power amplifier includes: a first amplifying circuit element; a second amplifying circuit element; and an output transformer that includes a primary coil and a secondary coil. An end of the primary coil is connected to an output terminal of the first amplifying circuit element. Another end of the primary coil is connected to an output terminal of the second amplifying circuit element. An end of the secondary coil is connected to an output terminal of the power amplifier. The first amplifying circuit element and the second amplifying circuit element are disposed on the first principal surface. The first circuit component is disposed on the second principal surface.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is based on and claims priority of JapanesePatent Applications No. 2019-186318 filed on Oct. 9, 2019 and No.2020-057833, filed on Mar. 27, 2020. The entire disclosures of theabove-identified applications, including the specifications, drawingsand claims are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates to a radio frequency module and acommunication device.

BACKGROUND

A power amplifier that amplifies a radio frequency (RF) transmissionsignal is provided in a mobile communication apparatus such as a mobilephone.

Japanese Unexamined Patent Application Publication No. 2010-118916discloses a difference amplifying type power amplifier that includes afirst transistor to which a non-inverted input signal is input, a secondtransistor to which an inverted input signal is input, and a transformerdisposed on the output terminal side of the first transistor and thesecond transistor. The transformer includes two magnetically coupledprimary coils and one secondary coil. The two primary coils areconnected in parallel, and are each magnetically coupled with thesecondary coil, so that the input impedance of the primary coils can bedecreased without decreasing the Q factor. Accordingly, power gain canbe improved.

SUMMARY Technical Problems

However, as recognized by the present inventor, if the differenceamplifying type power amplifier disclosed in Japanese Unexamined PatentApplication Publication No. 2010-118916 is achieved using one radiofrequency module, many circuit elements are included in the poweramplifier, which results in an increase in the size of the radiofrequency module.

The present disclosure has been conceived to solve the above-identifiedand other problems, and is to provide a small radio frequency modulethat includes a difference amplifying type power amplifier, and acommunication device that includes the radio frequency module.

Solutions

In order to achieve the above object, a radio frequency module accordingto an aspect of the present disclosure includes: a module board thatincludes a first principal surface and a second principal surface onopposite sides of the module board; a power amplifier configured toamplify a transmission signal; and a first circuit component. The poweramplifier includes: a first amplifying circuit element; a secondamplifying circuit element; and an output transformer that includes afirst coil and a second coil. An end of the first coil is connected toan output terminal of the first amplifying circuit element, and anotherend of the first coil is connected to an output terminal of the secondamplifying circuit element. An end of the second coil is connected to anoutput terminal of the power amplifier. The first amplifying circuitelement and the second amplifying circuit element are disposed on thefirst principal surface. The first circuit component is disposed on thesecond principal surface.

Advantageous Effects

According to the present disclosure, a small radio frequency module thatincludes a difference amplifying type power amplifier, and acommunication device can be provided.

BRIEF DESCRIPTION OF DRAWINGS

These and other advantages and features will become apparent from thefollowing description thereof taken in conjunction with the accompanyingDrawings, by way of non-limiting examples of embodiments disclosedherein.

FIG. 1 illustrates a circuit configuration of a radio frequency module(or RF front-end circuitry) and a communication device according to anembodiment.

FIG. 2 illustrates a circuit configuration of a difference amplifyingtype power amplifier.

FIG. 3A is a schematic diagram illustrating a planar configuration of aradio frequency module according to an example.

FIG. 3B is a schematic diagram illustrating a cross-sectionalconfiguration of the radio frequency module according to the example.

FIG. 3C is a schematic diagram illustrating a cross-sectionalconfiguration of a radio frequency module according to Variation 1.

FIG. 4A is a schematic diagram illustrating a cross-sectionalconfiguration of an output transformer according to Variation 2.

FIG. 4B is a schematic diagram illustrating a cross-sectionalconfiguration of the output transformer according to Variation 3.

FIG. 4C is a schematic diagram illustrating a cross-sectionalconfiguration of the output transformer according to Variation 4.

FIG. 5 illustrates a circuit configuration of a radio frequency moduleand a communication device according to Variation 5.

FIG. 6A is a schematic diagram illustrating a planar configuration of aradio frequency module according to Variation 6.

FIG. 6B is a schematic diagram illustrating a cross-sectionalconfiguration of the radio frequency module according to Variation 6.

FIG. 7A is a schematic diagram illustrating a planar configuration of aradio frequency module according to Variation 7.

FIG. 7B is a schematic diagram illustrating a cross-sectionalconfiguration of the radio frequency module according to Variation 7.

DESCRIPTION OF EMBODIMENTS

The following describes in detail embodiments of the present disclosure.Note that the embodiments described below each show a general orspecific example. The numerical values, shapes, materials, elements, thearrangement and connection of the elements, and others indicated in thefollowing embodiments are mere examples, and therefore are not intendedto limit the present disclosure. Thus, among the elements in thefollowing examples and variations, elements not recited in anyindependent claim are described as arbitrary elements. In addition, thesizes of elements and the ratios of the sizes illustrated in thedrawings are not necessarily accurate. Throughout the drawings, the samenumeral is given to substantially the same element, and redundantdescription may be omitted or simplified.

In the following, a term that indicates a relation between elements suchas “parallel” or “perpendicular”, a term that indicates the shape of anelement such as “rectangular”, and a numerical range do not necessarilyhave only strict meanings, and also have substantially equivalentmeanings that include a difference of about several percent, forexample.

In the following, regarding A, B, and C mounted on a board, “C isdisposed between A and B in a plan view of a board (or a principalsurface of a board)” means at least one of line segments that connectarbitrary points in A and B passes through a region of C in a plan viewof a board. A plan view of a board means that a board and a circuitelement mounted on the board are viewed, being orthogonally projectedonto a plane parallel to a principle surface of the board.

In the following, a “transmission path” means a transfer route thatincludes, for instance, a line through which a radio frequencytransmission signal propagates, an electrode directly connected to theline, and a terminal directly connected to the line or the electrode.Further, a “reception path” means a transfer route that includes, forinstance, a line through which a radio frequency reception signalpropagates, an electrode directly connected to the line, and a terminaldirectly connected to the line or the electrode. In addition, a“transmission and reception path” means a transfer route that includes,for instance, a line through which a radio frequency transmission signaland a radio frequency reception signal propagate, an electrode directlyconnected to the line, and a terminal directly connected to the line orthe electrode. Furthermore, as used herein the terms “circuit” or“circuitry” means one or more circuits, including discrete circuit(s) aswell as circuit board(s) and combinations thereof.

Embodiment

[1. Circuit Configuration of Radio Frequency Module 1 and CommunicationDevice 5]

FIG. 1 illustrates a circuit configuration of radio frequency module 1and communication device 5 according to an embodiment. As illustrated inFIG. 1, communication device 5 includes radio frequency module 1,antenna 2, radio frequency (RF) signal processing circuit (RF integratedcircuit (RFIC)) 3, and baseband signal processing circuit (BB integratedcircuit (BBIC)) 4. In this exemplary configuration the communicationdevice is a multi-band transceiver. As used in this specification theterm “module”, as used with “radio frequency module”, or “RF front-endmodule” should be construed as circuitry (programmable, as well asdiscrete) and associated circuit components, such as circuit boards, RFshielding, etc.

RFIC 3 is an RF signal processing circuit that processes radio frequencysignals transmitted and received by antenna 2. Specifically, RFIC 3processes a reception signal input through a reception path of radiofrequency module 1 by down-conversion, for instance, and outputs areception signal generated by being processed to BBIC 4. RFIC 3processes a transmission signal input from BBIC 4 by up-conversion, forinstance, and outputs a transmission signal generated by being processedto a transmission path of radio frequency module 1.

BBIC 4 is a circuit that processes signals using an intermediatefrequency band lower than the frequency range of a radio frequencysignal transferred in radio frequency module 1. A signal processed byBBIC 4 is used, for example, as an image signal for image display or asan audio signal for talk through a loudspeaker.

RFIC 3 also has a function as a controller that controls connection madeby switches 51, 52, 53, and 54 included in radio frequency module 1,based on a communication band (a frequency band) to be used.Specifically, RFIC 3 changes connection made by switches 51 to 54included in radio frequency module 1 according to a control signal (notillustrated). Note that the controller may be disposed outside RFIC 3,and may be disposed in radio frequency module 1 or BBIC 4, for example.Moreover, in one example the controller is a remote computer, or adistributed computer system that communicates with the radio frequencymodule 1 via a wireless or wired connection. Likewise, in anotherexample, the controller is a local controller with a user interface thatconverts input signals into control commands that control thecommunication device 5 as well as subcomponents, such as the RF module1.

Antenna 2 is connected to antenna connection terminal 100 of radiofrequency module 1, radiates a radio frequency signal output from radiofrequency module 1, and receives and outputs a radio frequency signalfrom the outside to radio frequency module 1.

Note that antenna 2 and BBIC 4 are not necessarily included incommunication device 5 according to the present embodiment.

Next, a detailed configuration of radio frequency module 1 is to bedescribed.

As illustrated in FIG. 1, radio frequency module 1 includes antennaconnection terminal 100, power amplifiers 11 and 12, low noiseamplifiers (LNAs) 21 and 22, transmission filters 61T and 62T, receptionfilters 61R and 62R, filter 63, reception input matching circuit 40,matching circuits 71, 72, and 73, switches 51, 52, 53, and 54, anddiplexer 60.

Antenna connection terminal 100 is an example of an input/outputterminal, and is an antenna common terminal connected to antenna 2.

Power amplifier 11 is a differential amplifier that amplifies radiofrequency signals, input through transmission input terminal 111, ofcommunication band A (a first communication band) and communication bandB (a second communication band) that belong to a first frequency bandgroup. Transmission power amplifier 12 is a differential amplifier thatamplifies radio frequency signals, input through transmission inputterminal 112, of communication band C that belongs to a second frequencyband group having different frequency bands from the first frequencyband group.

Low noise amplifier 21 amplifies radio frequency signals ofcommunication band A and communication band B while maintaining noiselow, and outputs the amplified signals to reception output terminal 121.Reception low noise amplifier 22 amplifies a radio frequency signal ofcommunication band C while maintaining noise low, and outputs theamplified signal to reception output terminal 122.

Transmission filter 61T is disposed on transmission path AT thatconnects power amplifier 11 and antenna connection terminal 100, andpasses a transmission signal of the transmission band of communicationband A, within a transmission signal amplified by power amplifier 11.Transmission filter 62T is disposed on transmission path BT thatconnects power amplifier 11 and antenna connection terminal 100, andpasses a transmission signal of the transmission band of communicationband B, within a transmission signal amplified by power amplifier 11.

Reception filter 61R is disposed on reception path AR that connects lownoise amplifier 21 and antenna connection terminal 100, and passes areception signal of the reception band of communication band A, within areception signal input through antenna connection terminal 100.Reception filter 62R is disposed on reception path BR that connects lownoise amplifier 21 and antenna connection terminal 100, and passes areception signal of the reception band of communication band B, within areception signal input through antenna connection terminal 100.

Transmission filter 61T and reception filter 61R are included induplexer 61 having a passband that is communication band A. Duplexer 61transfers a transmission signal and a reception signal of communicationband A, using the frequency division duplex (FDD) scheme. Transmissionfilter 62T and reception filter 62R are included in duplexer 62 having apassband that is communication band B. Duplexer 62 transfers atransmission signal and a reception signal of communication band B usingthe FDD scheme.

Note that duplexers 61 and 62 may each be a multiplexer that includesonly a plurality of transmission filters, a multiplexer that includesonly a plurality of reception filters, or a multiplexer that includes aplurality of duplexers.

Filter 63 is disposed on a path that connects switch 53 and switch 54,passes a transmission signal of communication band C within atransmission signal amplified by power amplifier 11, and passes areception signal of communication band C within a reception signal inputthrough antenna connection terminal 100. Filter 63 passes a transmissionsignal and a reception signal of communication band C using the timedivision duplex (TDD) scheme, according to switching operation of switch53.

An end of transmission path AT is connected to transmission inputterminal 111, and the other end of transmission path AT is connected toantenna connection terminal 100. An end of transmission path BT isconnected to transmission input terminal 111, and the other end oftransmission path BT is connected to antenna connection terminal 100. Anend of transmission path CT is connected to transmission input terminal112, and the other end of transmission path CT is connected to antennaconnection terminal 100.

One end of reception path AR is connected to antenna connection terminal100, and the other end of reception path AR is connected to receptionoutput terminal 121. One end of reception path BR is connected toantenna connection terminal 100, and the other end of reception path BRis connected to reception output terminal 121. One end of reception pathCR is connected to antenna connection terminal 100, and the other end ofreception path CR is connected to reception output terminal 122.

An end of transmission and reception path CTR is connected to switch 53,and the other end of transmission and reception path CTR is connected toantenna connection terminal 100. Specifically, transmission andreception path CTR includes a portion of transmission path CT and aportion of reception path CR.

Reception input matching circuit 40 includes matching circuits 41 and42. Matching circuit 41 is disposed on reception paths that connect lownoise amplifier 21 to reception filters 61R and 62R, and matches theimpedance between low noise amplifier 21 and reception filter 61R andthe impedance between low noise amplifier 21 and reception filter 62R.Matching circuit 42 is disposed on a reception path that connects lownoise amplifier 22 and filter 63, and matches the impedance between lownoise amplifier 22 and filter 63.

Switch 51 includes a common terminal and two selection terminals. Thecommon terminal of switch 51 is connected to output terminal 116 ofpower amplifier 11. One selection terminal out of the selectionterminals of switch 51 is connected to transmission filter 61T, and theother selection terminal out of the selection terminals of switch 51 isconnected to transmission filter 62T. This connection configurationallows switch 51 to switch between connecting the common terminal to theone selection terminal and connecting the common terminal to the otherselection terminal. Specifically, switch 51 switches between connectingpower amplifier 11 to transmission filter 61T and connectingtransmission power amplifier 11 to transmission filter 62T. Switch 51includes a single pole double throw (SPDT) switch circuit, for example.

Switch 52 includes a common terminal and two selection terminals. Thecommon terminal of switch 52 is connected to an input terminal of lownoise amplifier 21 via matching circuit 41. One selection terminal outof the selection terminals of switch 52 is connected to reception filter61R, and the other selection terminal out of the selection terminals ofswitch 52 is connected to reception filter 62R. This connectionconfiguration allows switch 52 to switch between connecting anddisconnecting the common terminal to/from the one selection terminal,and connecting and disconnecting the common terminal to/from the otherselection terminal. Specifically, switch 52 switches between connectingand disconnecting low noise amplifier 21 to/from reception filter 61R,and switches between connecting and disconnecting low noise amplifier 21to/from reception filter 62R. Switch 52 includes an SPDT switch circuit,for example.

Switch 53 includes a common terminal and two selection terminals. Thecommon terminal of switch 53 is connected to filter 63. One selectionterminal out of the selection terminals of switch 53 is connected tooutput terminal 126 of power amplifier 12, and the other selectionterminal out of the selection terminals of switch 53 is connected to aninput terminal of low noise amplifier 22 via matching circuit 42. Thisconnection configuration allows switch 53 to switch between connectingand disconnecting the common terminal to/from the one selectionterminal, and connecting and disconnecting the common terminal to/fromthe other selection terminal. Specifically, switch 53 switches betweenconnecting and disconnecting filter 63 to/from power amplifier 12, andswitches between connecting and disconnecting filter 63 to/from lownoise amplifier 22. Switch 53 includes an SPDT switch circuit, forexample.

Switch 54 is an example of an antenna switch, is connected to antennaconnection terminal 100 via diplexer 60, and switches among (1)connecting antenna connection terminal 100 to transmission path AT andreception path AR, (2) connecting antenna connection terminal 100 totransmission path BT and reception path BR, and (3) connecting antennaconnection terminal 100 to transmission and reception path CTR. Notethat switch 54 includes a multiple connection switch circuit that allowstwo or more simultaneous connections of (1) to (3) above.

Matching circuit 71 is disposed on a path that connects switch 54 andduplexer 61, and matches the impedance between (i) duplexer 61 and (ii)antenna 2 and switch 54. Matching circuit 72 is disposed on a path thatconnects switch 54 and duplexer 62, and matches the impedance between(i) duplexer 62 and (ii) antenna 2 and switch 54. Matching circuit 73 isdisposed on a path that connects switch 54 and filter 63, and matchesthe impedance between (i) filter 63 and (ii) antenna 2 and switch 54.

Diplexer 60 is an example of a multiplexer, and includes filters 60L and60H. Filter 60L has a passband whose frequency range includes the firstfrequency band group and the second frequency band group, and filter 60Hhas a passband whose frequency range includes another frequency bandgroup having different frequency bands from the first frequency bandgroup and the second frequency band group. One terminal of filter 60Land one terminal of filter 60H are connected in common to antennaconnection terminal 100. Filters 60L and 60H are each an LC filter thatincludes at least one of a chip inductor or a chip capacitor, forexample. Note that when the first frequency band group and the secondfrequency band group have lower frequency bands than the other frequencyband group, filter 60L may be a lowpass filter, and filter 60H may be ahighpass filter.

Note that transmission filters 61T and 62T and reception filters 61R,62R, and 63 described above may each be one of, for example, an acousticwave filter that uses surface acoustic waves (SAWs), an acoustic wavefilter that uses bulk acoustic waves (BAWs), an LC resonance filter, anda dielectric filter, and furthermore, are not limited to those filters.

Matching circuits 41, 42, and 71 to 73 are elements that are notnecessarily included in the radio frequency module according to thepresent disclosure.

In the configuration of radio frequency module 1, power amplifier 11,switch 51, transmission filter 61T, matching circuit 71, switch 54, andfilter 60L are included in a first transmission circuit that transfers atransmission signal of communication band A towards antenna connectionterminal 100. Filter 60L, switch 54, matching circuit 71, receptionfilter 61R, switch 52, matching circuit 41, and low noise amplifier 21are included in a first reception circuit that transfers a receptionsignal of communication band A from antenna 2 via antenna connectionterminal 100.

Power amplifier 11, switch 51, transmission filter 62T, matching circuit72, switch 54, and filter 60L are included in a second transmissioncircuit that transfers a transmission signal of communication band Btowards antenna connection terminal 100. Filter 60L, switch 54, matchingcircuit 72, reception filter 62R, switch 52, matching circuit 41, andlow noise amplifier 21 are included in a second reception circuit thattransfers a reception signal of communication band B from antenna 2 viaantenna connection terminal 100.

Power amplifier 12, switch 53, filter 63, matching circuit 73, switch54, and filter 60L are included in a third transmission circuit thattransfers a transmission signal of communication band C towards antennaconnection terminal 100. Filter 60L, switch 54, matching circuit 73,filter 63, switch 53, matching circuit 42, and low noise amplifier 22are included in a third reception circuit that transfers a receptionsignal of communication band C from antenna 2 via antenna connectionterminal 100.

According to the above circuit configuration, radio frequency module 1can carry out at least one of simultaneous transmission, simultaneousreception, or simultaneous transmission and reception of a radiofrequency signal of communication band A or B and a radio frequencysignal of communication band C.

Note that in the radio frequency module according to the presentdisclosure, the three transmission circuits and the three receptioncircuits may not be connected to antenna connection terminal 100 viaswitch 54, and may be connected to antenna 2 via different terminals.The radio frequency module according to the present disclosure mayinclude at least one of the first transmission circuit, the secondtransmission circuit, or the third transmission circuit.

In the radio frequency module according to the present disclosure, thefirst transmission circuit may include at least one of power amplifier11, transmission filter 61T, switch 54, or filter 60L. The secondtransmission circuit may include at least one of power amplifier 11,transmission filter 62T, switch 54, or filter 60L. The thirdtransmission circuit may include at least one of power amplifier 12,filter 63, switch 54, or filter 60L.

Reception low noise amplifiers 21 and 22 and switches 51 to 54 may beformed into one semiconductor integrated circuit (IC). Furthermore, thesemiconductor IC may also include transmission power amplifiers 11 and12. The semiconductor IC includes a complementary metal oxidesemiconductor (CMOS), for example. Specifically, the semiconductor IC isformed by the silicon on insulator (SOI) process. Accordingly, thesemiconductor IC can be manufactured at a low cost. Note that thesemiconductor IC may include at least one of GaAs, SiGe, or GaN. Thus, aradio frequency signal having high amplification quality and high noisequality can be output.

Here, the circuit configuration of power amplifiers 11 and 12 is to bedescribed in detail.

FIG. 2 illustrates a circuit configuration of power amplifier 11. Asillustrated in FIG. 2, power amplifier 11 includes input terminal 115,output terminal 116, amplifying element 11A (a first amplifying circuitelement), amplifying element 11B (a second amplifying circuit element),amplifying element 11C, output transformer (transformer) 31, capacitor32, and interstage transformer (unbalance-balance transforming element)33.

An input terminal of amplifying element 11C is connected to inputterminal 115, and an output terminal of amplifying element 11C isconnected to an unbalance terminal of interstage transformer 33. Onebalance terminal of interstage transformer 33 is connected to an inputterminal of amplifying element 11A, and the other balance terminal ofinterstage transformer 33 is connected to an input terminal ofamplifying element 11B.

A radio frequency signal input through input terminal 115 is amplifiedby amplifying element 11C in a state in which bias voltage Vcc1 isapplied to amplifying element 11C. Interstage transformer appliesunbalance-balance transform to the amplified radio frequency signal. Atthis time, a non-inverted input signal is output through the one balanceterminal of interstage transformer 33, and an inverted input signal isoutput through the other balance terminal of interstage transformer 33.

Output transformer 31 includes primary coil 31 a (a first coil) andsecondary coil 31 b (a second coil). An end of primary coil 31 a isconnected to an output terminal of amplifying element 11A, and the otherend of primary coil 31 a is connected to an output terminal ofamplifying element 11B. Bias voltage Vcc2 is supplied to the middlepoint of primary coil 31 a. An end of secondary coil 31 b is connectedto output terminal 116, and the other end of secondary coil 31 b isconnected to the ground. In other words, output transformer 31 isconnected between output terminal 116 and the output terminals ofamplifying elements 11A and 11B.

Capacitor 32 is connected between the output terminal of amplifyingelement 11A and the output terminal of amplifying element 11B.

Impedance of a non-inverted input signal amplified by amplifying element11A and impedance of an inverted input signal amplified by amplifyingelement 11B are transformed by output transformer 31 and capacitor 32,being in antiphase each other. Specifically, output transformer 31 andcapacitor 32 matches output impedance of power amplifier 11 at outputterminal 116 to input impedance of switch 51 and transmission filters61T and 62T illustrated in FIG. 1. Note that a capacitive elementconnected between the ground and a path that connects output terminal116 and secondary coil 31 b contributes to the impedance matching. Notethat the capacitive element may be disposed in series on the path thatconnects output terminal 116 and secondary coil 31 b, or may not beincluded.

According to the circuit configuration of power amplifier 11, amplifyingelements 11A and 11B operate in antiphase with each other. At this time,fundamental-wave currents flow through amplifying elements 11A and 11Bin antiphase with each other, that is, in opposite directions, and thusfundamental-wave currents do not flow into a ground line and a powersupply line disposed at a substantially equal distance from amplifyingelements 11A and 11B. Accordingly, inflow of unnecessary currents to theabove lines can be disregarded, and thus decrease in power gain that canbe seen in a conventional power amplifier can be reduced. Further, anoninverted signal and an inverted signal amplified by amplifyingelements 11A and 11B are combined, and thus noise componentssuperimposed similarly on the signals can be cancelled out, andunnecessary waves such as harmonic components, for example, can bedecreased.

Note that amplifying element 11C is not necessarily included in poweramplifier 11. A component that transforms an unbalanced input signalinto a non-inverted input signal and an inverted input signal is notlimited to interstage transformer 33. Capacitor 32 is not an essentialelement for impedance matching.

Amplifying elements 11A, 11B, and 11C and low noise amplifiers 21 and 22each include a field effect transistor (FET) or a hetero-bipolartransistor (HBT) made of a Si-based CMOS or GaAs, for example.

Note that power amplifier 12 includes input terminal 125, outputterminal 126, amplifying elements 12A and 12B, amplifying element 12C,output transformer 36, capacitor 37, and interstage transformer 38, andhas a circuit configuration the same as the circuit configuration ofpower amplifier 11 illustrated in FIG. 2.

Here, when radio frequency module 1 is mounted on a single mountingsubstrate, many circuit elements are included in power amplifiers 11 and12 (such as amplifying elements 11A to 11C and 12A to 12C, interstagetransformers 33 and 38, output transformers 31 and 36, and capacitors 32and 37), and thus the size of radio frequency module 1 is increased. Ifthe elements are mounted densely for size reduction, a high-powertransmission signal output from power amplifier 11 or 12 is coupled withat least one of the circuit components included in radio frequencymodule 1 via a magnetic field, an electric field, or an electromagneticfield, or high-power transmission signals output from power amplifiers11 and 12 are coupled via a magnetic field, an electric field, or anelectromagnetic field, which leads to a problem that transfer loss of aradio frequency signal transferred in radio frequency module 1increases.

To address this, radio frequency module 1 according to the presentembodiment has a configuration that reduces the size of radio frequencymodule 1 while preventing power amplifiers 11 and 12 and other circuitcomponents from being coupled with one another via an electric field, amagnetic field, or an electromagnetic field. The following describes aconfiguration of radio frequency module 1 that archives both preventingcoupling via an electric field, a magnetic field, or an electromagneticfield, and reducing the size thereof.

[2. Arrangement of Circuit Elements of Radio Frequency Module 1AAccording to Example]

FIG. 3A is a schematic diagram illustrating a planar configuration ofradio frequency module 1A according to an example. FIG. 3B is aschematic diagram illustrating a cross-sectional configuration of radiofrequency module 1A according to the example and specifically,illustrates a cross section taken along line IIIB to IIIB in FIG. 3A.Note that (a) of FIG. 3A illustrates a layout of circuit elements whenprincipal surface 91 a out of principal surfaces 91 a and 91 b onopposite sides of module board 91 is viewed from the positive z-axis. Onthe other hand, (b) of FIG. 3A is a perspective view of the layout ofcircuit elements when principal surface 91 b is viewed from the positivez-axis. FIG. 3A illustrates output transformers 31 and 36 formed (ordisposed) inside of module board 91 indicated with dashed lines.

Radio frequency module 1A according to the example shows a specificarrangement of circuit elements included in radio frequency module 1according to the embodiment.

As illustrated in FIGS. 3A and 3B, radio frequency module 1A accordingto this example further includes module board 91 and resin members 92and 93, in addition to the circuit configuration illustrated in FIG. 1.

Module board 91 is a board which includes principal surface 91 a (afirst principal surface) and principal surface 91 b (a second principalsurface) on opposite sides of module board 91, and on which the abovetransmission circuits and the above reception circuits are mounted. Asmodule board 91, one of a low temperature co-fired ceramics (LTCC)board, a high temperature co-fired ceramics (HTCC) board, acomponent-embedded board, a board that includes a redistribution layer(RDL), and a printed circuit board, each having a stacked structure of aplurality of dielectric layers, is used, for example. Note that onmodule board 91, antenna connection terminal 100, transmission inputterminals 111 and 112, reception output terminals 121 and 122, inputterminals 115 and 125, and output terminals 116 and 126 may be formed.

Resin member 92 is disposed on principal surface 91 a of module board91, covers at least partially the transmission circuits, at leastpartially the reception circuits, and principal surface 91 a of moduleboard 91, and has a function of ensuring reliability of mechanicalstrength and moisture resistance, for instance, of the circuit elementsincluded in the transmission circuits and the reception circuits. Resinmember 93 is disposed on principal surface 91 b of module board 91,covers at least partially the transmission circuits, at least partiallythe reception circuits, and principal surface 91 b of module board 91,and has a function of ensuring reliability of mechanical strength andmoisture resistance, for instance, of the circuit elements included inthe transmission circuits and the reception circuits. Note that resinmembers 92 and 93 are elements not necessarily included in the radiofrequency module according to the present disclosure.

As illustrated in FIGS. 3A and 3B, in radio frequency module 1Aaccording to this example, amplifying elements 11A, 11B, 12A, and 12B,capacitors 32 and 37, duplexers 61 and 62, filter 63, matching circuits41 and 42, and diplexer 60 are mounted on principal surface 91 a ofmodule board 91. On the other hand, low noise amplifiers 21 and 22 andswitches 51, 52, 53, and 54 are mounted on principal surface 91 b ofmodule board 91. Output transformers 31 and 36 are formed inside ofmodule board 91. Note that although not illustrated in FIGS. 3A and 3B,matching circuits 71 to 73 and interstage transformers 33 and 38 may bemounted on either of principal surfaces 91 a and 91 b of module board91, or may be provided inside of module board 91.

Note that although not illustrated in FIG. 3A, lines that constitutetransmission paths AT, BT, and CT and reception paths AR, BR, and CRillustrated in FIG. 1 are formed inside of module board 91 and onprincipal surfaces 91 a and 91 b. The above lines may be bonding wireshaving ends joined to any of principal surfaces 91 a and 91 b andcircuit elements included in radio frequency module 1A, or may beterminals, electrodes, or lines formed on the surfaces of circuitelements included in radio frequency module 1A.

In this example, low noise amplifiers 21 and 22 and switches 51, 52, 53,and 54 are first circuit components, and disposed on principal surface91 b. On the other hand, amplifying elements 11A, 11B, 12A, and 12B aredisposed on principal surface 91 a.

According to the above configuration, amplifying elements 11A, 11B, 12A,and 12B and the first circuit components are disposed on two sides ofmodule board 91, with module board 91 therebetween. Accordingly, radiofrequency module 1 can be miniaturized as compared with a configurationin which all amplifying elements 11A, 11B, 12A, and 12B and the firstcircuit components are disposed on one side of module board 91.Amplifying elements 11A, 11B, 12A, and 12B and the first circuitcomponents are disposed with module board 91 therebetween, and thustransmission signals output from amplifying elements 11A, 11B, 12A, and12B can be prevented from being coupled with the first circuitcomponents via an electric field, a magnetic field, or anelectromagnetic field. Accordingly, small radio frequency module 1 inwhich transfer loss of the transmission signals is decreased can beprovided.

Further, transmission signals output from amplifying elements 11A, 11B,12A, and 12B can be prevented from being coupled with the first circuitcomponents via an electric field, a magnetic field, or anelectromagnetic field, and thus a transmission signal of communicationband A, B, or C can be prevented from flowing into one or more ofreception paths AR, BR, and CR without passing through transmissionfilter 61T or 62T and switch 54, for example. Further, harmonics thatoccur from amplifying elements 11A, 11B, 12A, and 12B and moreover,spurious waves due to intermodulation distortion caused by atransmission signal amplified by transmission power amplifier 11 and atransmission signal amplified by transmission power amplifier 12 can beprevented from sneaking into one or more of reception paths AR, BR, andCR. Accordingly, isolation of the transmission circuits from thereception circuits improves, and thus this can reduce a decrease inreception sensitivity caused by the transmission signal, harmonics, andspurious waves due to intermodulation distortion sneaking into thereception paths.

Note that in radio frequency module 1A according to this example, lownoise amplifiers 21 and 22 and switches 51 to 54 may be formed in onesemiconductor IC 10.

Although radio frequency module 1A according to this example has aconfiguration in which low noise amplifiers 21 and 22 and switches 51,52, 53, and 54 are disposed on principal surface 91 b, yet amplifyingelements 11A, 11B, 12A, and 12B may be disposed on principal surface 91a, and at least one of the first circuit components may be disposed onprincipal surface 91 b. For example, when at least one of switches 51,52, 53, and 54 is a first circuit component, low noise amplifiers 21 and22 may be disposed on principal surface 91 a.

Accordingly, smaller radio frequency module 1 in which transfer loss ofthe above transmission signals is decreased can be provided, as comparedwith a radio frequency module having a configuration in which amplifyingelements 11A, 11B, 12A, and 12B and all the first circuit components aredisposed on the same principal surface.

The first circuit component may be at least one of:

(1) low noise amplifier 21 or 22

(2) an inductor of matching circuit 41 or an inductor of matchingcircuit 42

(3) one of switches 51 to 54

(4) one of transmission filters 61T and 62T, reception filters 61R and62R, and filter 63

(5) diplexer 60

(6) capacitor 32 or 37

Note that desirably, module board 91 has a multilayer structure in whicha plurality of dielectric layers are stacked, and a ground electrodepattern is formed on at least one of the dielectric layers. Accordingly,the electromagnetic field shielding function of module board 91improves.

Among the circuit components shown in (1) to (6) above, a first circuitcomponent on module board 91 on another side of which amplifyingelements 11A, 11B, 12A, and 12B are disposed may be disposed onreception path AR, BR, or CR. Specifically, the first circuit componentmay be any of (1) low noise amplifier 21 or 22, (2) the inductor ofmatching circuit 41 or the inductor of matching circuit 42, (3) switch53 or 54, (4) one of reception filters 61R and 62R and filter 63, and(5) diplexer 60. In this case, desirably, the first circuit componentsdisposed on principal surface 91 b and output transformers 31 and 36 donot overlap in a plan view of module board 91, as illustrated in FIG.3A.

Accordingly, transmission signals output from amplifying elements 11A,11B, 12A, and 12B, and transferred through output transformers 31 and 36can be effectively prevented from being coupled with the first circuitcomponents disposed on the reception paths via a magnetic field or anelectromagnetic field. Accordingly, isolation of power amplifiers 11 and12 from the reception circuits improves, and thus the transmissionsignals, harmonics, and spurious waves due to intermodulation distortioncan be effectively prevented from sneaking into the reception paths,thus reducing a decrease in reception sensitivity.

Among the circuit components indicated in (1) to (6) above, a firstcircuit component on module board 91 on another side of which amplifyingelements 11A, 11B, 12A, and 12B are disposed is more desirably (1) lownoise amplifier 21 or 22. In this case, desirably, low noise amplifiers21 and 22 disposed on principal surface 91 b and output transformers 31and 36 do not overlap in a plan view of module board 91, as illustratedin FIG. 3A.

Accordingly, transmission signals output from amplifying elements 11A,11B, 12A, and 12B, and transferred through output transformers 31 and 36can be prevented from being coupled with one or both of low noiseamplifiers 21 and 22 via a magnetic field or an electromagnetic field.Thus, isolation of power amplifiers 11 and 12 from the one or both oflow noise amplifiers 21 and 22 improves, and thus the transmissionsignals, harmonics, and spurious waves due to intermodulation distortioncan be still further prevented from sneaking into the reception paths,thus reducing a decrease in reception sensitivity.

In radio frequency module 1A according to this example, in a plan viewof module board 91, amplifying elements 11A and 11B and outputtransformer 31 do not overlap, and amplifying elements 12A and 12B andoutput transformer 36 do not overlap, desirably, as illustrated in FIG.3A.

Accordingly, amplifying elements 11A and 11B and secondary coil 31 b ofoutput transformer 31 can be prevented from being unnecessarily coupledwith one another via a magnetic field or an electromagnetic field, andamplifying elements 12A and 12B and secondary coil 36 b of outputtransformer 36 can be prevented from being unnecessarily coupled withone another via a magnetic field or an electromagnetic field.Consequently, the degree of impedance matching between power amplifiers11 and 12 can be prevented from decreasing, thus reducing an increase intransfer loss and an increase in spurious waves.

In radio frequency module 1A according to this example, a plurality ofexternal-connection terminals 150 are disposed on principal surface 91 bof module board 91. Radio frequency module 1A exchanges electricalsignals with the motherboard disposed on the negative z-axis side ofradio frequency module 1A, via external-connection terminals 150.Potential of some of external-connection terminals 150 are set to theground potential of the motherboard. On principal surface 91 b facingthe motherboard out of principal surfaces 91 a and 91 b, poweramplifiers 11 and 12 whose height is not readily decreased are notdisposed, and low noise amplifiers 21 and 22 and switches 51 to 54 whoseheight is readily decreased are disposed, and thus the height of radiofrequency module 1A as a whole can be decreased. Further,external-connection terminals 150 used as ground electrodes are disposedaround low noise amplifiers 21 and 22 that greatly affect receptionsensitivity of the reception circuits, and thus deterioration ofreception sensitivity of the reception circuits can be reduced.

Note that external-connection terminals 150 may be columnar electrodespassing through resin member 93 in the z-axis direction as illustratedin FIGS. 3A and 3B, or may be bump electrodes 151 formed on principalsurface 91 b as in radio frequency module 1B according to Variation 1illustrated in FIG. 3C. In this case, resin member 93 may not beprovided on principal surface 91 b.

Power amplifiers 11 and 12 are components that generate a great amountof heat, out of circuit components included in radio frequency module1A. In order to improve heat dissipation of radio frequency module 1A,it is important to dissipate heat generated by power amplifiers 11 and12 to the motherboard through heat dissipation paths having low heatresistance. If power amplifiers 11 and 12 are mounted on principalsurface 91 b, electrode lines connected to power amplifiers 11 and 12are disposed on principal surface 91 b. Accordingly, the heatdissipation paths include a heat dissipation path along only a planarline pattern (in the xy plane direction) on principal surface 91 b. Theplanar line pattern is formed of a thin metal film, and thus has highheat resistance. Accordingly, if power amplifiers 11 and 12 are disposedon principal surface 91 b, heat dissipation deteriorates.

In contrast, if power amplifiers 11 and 12 are mounted on principalsurface 91 a as in this example, power amplifiers 11 and 12 andexternal-connection terminals 150 can be connected via penetratingelectrodes passing through module board 91 between principal surface 91a and principal surface 91 b. Accordingly, as heat dissipation paths forpower amplifiers 11 and 12, a heat dissipation path extending along onlya planar line pattern in the xy plane direction and having high heatresistance can be excluded from lines on and in module board 91. Thus,miniaturized radio frequency module 1A having improved heat dissipationfrom transmission power amplifiers 11 and 12 to the motherboard can beprovided.

According to the above configuration that improves heat dissipation ofradio frequency module 1A, penetrating electrodes andexternal-connection terminals, for instance, intended to dissipate heatare disposed in the region in positions opposite transmission poweramplifiers 11 and 12 in the z-axis direction, and thus it is desirablenot to dispose circuit components. Also from this viewpoint, it isdesirable that amplifying elements 11A and 11B and output transformer 31do not overlap, and amplifying elements 12A and 12B and outputtransformer 36 do not overlap, in a plan view of module board 91.

Note that output transformers 31 and 36 are formed inside of moduleboard 91 between principal surface 91 a and principal surface 91 b inradio frequency module 1A according to this example. According to this,it is not necessary to dispose output transformers 31 and 36 onprincipal surface 91 a or principal surface 91 b, and thus the area forradio frequency module 1A can be reduced. Note that in outputtransformer 31 formed inside of module board 91, for example, primarycoil 31 a and secondary coil 31 b are each formed in planar line pattern31 p in the xy plane direction. Primary coil 31 a and secondary coil 31b each formed in planar line pattern 31 p face each other within the xyplane or are disposed in opposite positions in the z-axis direction, soas to have predetermined magnetic coupling.

In radio frequency module 1A according to this example, as illustratedin FIGS. 3A and 3B, module board 91 includes ground electrode layer 95 gformed on principal surface 91 b in a direction parallel to thedirection of the xy plane. Here, in a plan view of module board 91,desirably, ground electrode layer 95 g is not formed in regions on bothprincipal surfaces 91 a and 91 b, which overlap formation region 30 inwhich output transformers 31 and 36 are formed.

According to this, it can be ensured that output transformers 31 and 36and a ground electrode are widely spaced apart, and thus transfer lossof transmission signals transferred through power amplifiers 11 and 12can be decreased.

Note that in this example, in a plan view of module board 91, groundelectrode layer 95 g is not formed in regions on both principal surfaces91 a and 91 b, which overlap formation region 30 in which outputtransformers 31 and 36 are formed, but a configuration in which groundelectrode layer 95 g is not formed in a region on one of principalsurface 91 a and principal surface 91 b, which overlaps formation region30 in which output transformers 31 and 36 are formed, may be adopted.Even in this case, transfer loss of transmission signals transferredthrough power amplifiers 11 and 12 can be decreased.

As illustrated in FIGS. 3A and 3B, in a plan view of module board 91, itis desirable that no circuit component is disposed in a region inprincipal surface 91 a or a region in principal surface 91 b, whichoverlaps the formation region in which output transformers 31 and 36 areformed.

Output transformers 31 and 36 transfer high-power transmission signalsamplified by power amplifiers 11 and 12, respectively, and thus Qfactors of inductors included in output transformers 31 and 36 aredesirably high. If one or more circuit components are in a region thatoverlaps output transformers 31 and 36 in the above plan view,electromagnetic fields formed by the inductors are influenced by the oneor more circuit components, and the Q factors of the inductors decrease,and power of transmission signals output from output transformers 31 and36 decreases. To address this, the above configuration can reduce adecrease in amplification performance of power amplifiers 11 and 12.

Note that in this example, output transformers 31 and 36 are formedinside of module board 91 between principal surface 91 a and principalsurface 91 b and offset toward principal surface 91 a. In this case, ina plan view of module board 91, no circuit component is disposed in aregion in principal surface 91 a that overlaps the formation region inwhich output transformers 31 and 36 are formed, and one or more circuitcomponents (not illustrated) may be disposed in a region in principalsurface 91 b that overlaps the formation region in which outputtransformers 31 and 36 are formed.

Even in this case, no circuit component is disposed in the above regionin principal surface 91 a closer to output transformers 31 and 36, andthus decreases in the Q factors of the inductors of output transformers31 and 36 can be reduced.

FIG. 4A is a schematic diagram of a cross-sectional configurationillustrating the position of output transformer 31 in radio frequencymodule 1C according to Variation 2. FIG. 4A illustrates the position ofoutput transformer 31 in the cross-sectional configuration of radiofrequency module 1C according to Variation 2. Note that the arrangementof circuit components other than output transformer 31 included in radiofrequency module 1C is the same as radio frequency module 1A accordingto the example. In radio frequency module 1C, output transformer 31 isformed inside of module board 91 between principal surface 91 a andprincipal surface 91 b and offset toward principal surface 91 b. In thiscase, in a plan view of module board 91, no circuit component isdisposed in a region in principal surface 91 b that overlaps theformation region in which output transformer 31 is formed, and one ormore circuit components (not illustrated) may be disposed in a region inprincipal surface 91 a that overlaps the formation region in whichoutput transformer 31 is formed.

Even in this case, no circuit component is disposed in the above regionin principal surface 91 b that is closer to output transformer 31, andthus a decrease in the Q factor of the inductor of output transformer 31can be reduced.

FIG. 4B is a schematic diagram of a cross-sectional configurationillustrating the position of output transformer 31 in radio frequencymodule 1D according to Variation 3. FIG. 4B illustrates the position ofoutput transformer 31 in the cross-sectional configuration of radiofrequency module 1D according to Variation 3. Note that the arrangementof circuit components other than output transformer 31 included in radiofrequency module 1D is the same as radio frequency module 1A accordingto the example. In radio frequency module 1D, output transformer 31 isdisposed on principal surface 91 b. Output transformer 31 is a chipinductor or capacitor, for example. In this case, desirably, no circuitcomponent is disposed in a region in principal surface 91 a thatoverlaps the formation region in which output transformer 31 is formed,in a plan view of module board 91.

According to this configuration, no circuit component is disposed in theabove region in principal surface 91 a, and thus a decrease in the Qfactor of the inductor of output transformer 31 can be reduced.

FIG. 4C is a schematic diagram of a cross-sectional configurationillustrating the position of output transformer 31 in radio frequencymodule 1E according to Variation 4. FIG. 4C illustrates the position ofoutput transformer 31 in the cross-sectional configuration of radiofrequency module 1E according to Variation 4. Note that the arrangementof circuit components other than output transformer 31 included in radiofrequency module 1E is the same as radio frequency module 1A accordingto the example. In radio frequency module 1E, output transformer 31 isdisposed on principal surface 91 a. Output transformer 31 is a chipinductor or capacitor, for example. In this case, desirably, no circuitcomponent is disposed in a region of principal surface 91 b thatoverlaps a formation region in which output transformer 31 is formed, ina plan view of module board 91.

According to this configuration, no circuit component is disposed in theabove area in principal surface 91 b, and thus a decrease in the Qfactor of the inductor of output transformer 31 can be reduced.

Note that the formation region in which output transformer 31 is formedis defined as follows. The formation region in which output transformer31 is formed is a minimum region that includes a formation region inwhich a primary coil is formed and a formation region in which asecondary coil is formed, in a plan view of module board 91.

Note that formation region 30 in which output transformer 31 is formedis defined as follows. Formation region 30 in which output transformer31 is formed is a minimum region that includes a formation region inwhich primary coil 31 a is formed and a formation region in whichsecondary coil 31 b is formed, in a plan view of module board 91.

Here, secondary coil 31 b is defined as a line conductor disposed alongprimary coil 31 a, in a section in which a first distance from primarycoil 31 a is substantially constant. At this time, portions of the lineconductor located on both sides of the above section are spaced apartfrom primary coil 31 a by a second distance longer than the firstdistance, and one end and the other end of secondary coil 31 b arepoints at which a distance from the line conductor to primary coil 31 achanges from the first distance to the second distance. Primary coil 31a is defined as a line conductor disposed along secondary coil 31 b, ina section in which the first distance from secondary coil 31 b issubstantially constant. At this time, portions of the line conductorlocated on both sides of the above section are spaced apart fromsecondary coil 31 b by the second distance longer than the firstdistance, and one end and the other end of primary coil 31 a are pointsat which a distance from the line conductor to secondary coil 31 bchanges from the first distance to the second distance.

Alternatively, secondary coil 31 b is defined as a line conductordisposed along primary coil 31 a, in a first section in which the linewidth is a substantially constant first width. Primary coil 31 a isdefined as a line conductor disposed along secondary coil 31 b, in thefirst section in which the line width is the substantially constantfirst width.

Alternatively, secondary coil 31 b is defined as a line conductordisposed along primary coil 31 a, in a first section in which thethickness is a substantially constant first thickness. Primary coil 31 ais defined as a line conductor disposed along secondary coil 31 b, inthe first section in which the thickness is the substantially constantfirst thickness.

Alternatively, secondary coil 31 b is defined as a line conductordisposed along primary coil 31 a, in a first section in which a degreeof coupling with primary coil 31 a is a substantially constant firstdegree of coupling. Further, primary coil 31 a is defined as a lineconductor disposed along secondary coil 31 b, in the first section inwhich a degree of coupling with secondary coil 31 b is a substantiallyconstant first degree of coupling.

In radio frequency module 1A according to this example, switch 51 isdisposed on principal surface 91 b, and duplexers 61 and 62 are disposedon principal surface 91 a, as illustrated in FIG. 3A.

According to this, switch 51 and duplexers 61 and 62 are disposed withmodule board 91 therebetween, and thus a high-power transmission signalthat passes through switch 51 can be prevented from flowing intoreception filters 61R and 62R without passing through transmissionfilters 61T and 62T. Accordingly, deterioration of reception sensitivityin reception paths AR and BR can be reduced.

In radio frequency module 1A according to this example, duplexers 61 and62 are disposed on principal surface 91 a, and low noise amplifier 21 isdisposed on principal surface 91 b, as illustrated in FIGS. 3A and 3B.In a plan view of module board 91, duplexers 61 and 62 and low noiseamplifier 21 at least partially overlap.

According to this, duplexers 61 and 62 and low noise amplifier 21 can beconnected with a short line, and thus transfer loss of a receptionsignal can be decreased.

[3. Circuit Configuration of Radio Frequency Module 1F and CommunicationDevice 5F According to Variation 5]

FIG. 5 illustrates a circuit configuration of radio frequency module 1Fand communication device 5F according to Variation 5. As illustrated inFIG. 5, communication device 5F includes radio frequency module 1F,antenna 2, RFIC 3, and BBIC 4. Communication device 5F according to thisvariation is different from communication device 5 according to theembodiment, only in the configuration of radio frequency module 1F.Accordingly, the following describes communication device 5F accordingto this variation, focusing on the configuration of radio frequencymodule 1F.

As illustrated in FIG. 5, radio frequency module 1F includes antennaconnection terminal 100, power amplifiers 11 and 12, low noiseamplifiers 21 and 22, transmission filters 61T and 62T, receptionfilters 61R and 62R, filter 63, reception input matching circuit 40,matching circuits 71, 72, and 73, switches 51, 52, 53, 54, 55, and 56,and diplexer 60. Radio frequency module 1F according to this variationis different from radio frequency module 1 according to the embodiment,in that switches 55 and 56 are added. In the following, description ofthe common points of radio frequency module 1F according to thisvariation to those of radio frequency module 1 according to theembodiment is omitted, and different points are mainly described.

Power amplifier 11 amplifies radio frequency signals, input throughtransmission input terminals 111 a and 111 b, of communication band A (afirst communication band) and communication band B (a secondcommunication band) that belong to the first frequency band group. Poweramplifier 12 is a differential amplifier that amplifies radio frequencysignals, input through transmission input terminals 112 a and 112 b, ofcommunication band C belonging to a second frequency band group havingdifferent frequency bands from the first frequency band group.

Switch 55 has a common terminal and two selection terminals. The commonterminal of switch 55 is connected to input terminal 115 of poweramplifier 11. One of the selection terminals of switch 55 is connectedto transmission input terminal 111 a, and the other selection terminalis connected to transmission input terminal 111 b. Switch 55 is disposedon the input terminal side of power amplifier 11. This connectionconfiguration allows switch 55 to switch between connecting poweramplifier 11 to transmission input terminal 111 a and connecting poweramplifier 11 to transmission input terminal 111 b. Switch 55 includes anSPDT switch circuit, for example.

Switch 56 includes a common terminal and two selection terminals. Thecommon terminal of switch 56 is connected to input terminal 125 of poweramplifier 12. One of the selection terminals of switch 56 is connectedto transmission input terminal 112 a, and the other selection terminalis connected to transmission input terminal 112 b. Switch 56 is disposedon the input terminal side of power amplifier 12. This connectionconfiguration allows switch 56 to switch between connecting poweramplifier 12 to transmission input terminal 112 a and connecting poweramplifier 12 to transmission input terminal 112 b. Switch 56 includes anSPDT switch circuit, for example.

For example, a transmission signal of communication band A is inputthrough transmission input terminal 111 a, and for example, atransmission signal of communication band B is input throughtransmission input terminal 111 b. For example, transmission signals ofcommunication band C are input through transmission input terminals 112a and 112 b.

A transmission signal of communication band A or B used in a fourthgeneration mobile communication system (4G), for example, may be inputthrough transmission input terminal 111 a, and a transmission signal ofcommunication band A or B used in a fifth generation mobilecommunication system (5G), for example, may be input throughtransmission input terminal 111 b. Further, a transmission signal ofcommunication band C used in 4G, for example, is input throughtransmission input terminal 112 a, and a transmission signal ofcommunication band C used in 5G, for example, may be input throughtransmission input terminal 112 b.

Note that switches 55 and 56 may be one SPDT switch circuit thatincludes a common terminal connected to one transmission input terminal(which is a first transmission input terminal) among transmission inputterminals 111 a, 111 b, 112 a, and 112 b, one selection terminalconnected to input terminal 115 of power amplifier 11, and anotherselection terminal connected to input terminal 125 of power amplifier12.

In this case, for example, a transmission signal of one of communicationband A, communication band B, and communication band C is selectivelyinput through the first transmission input terminal, the SPDT switchcircuit resulting from combining switches 55 and 56 switches betweenconnecting the first transmission input terminal to power amplifier 11and connecting the first transmission input terminal to power amplifier12, according to an input transmission signal. For example, a 4Gtransmission signal and a 5G transmission signal may be input throughthe first transmission input terminal, and the above switch circuit mayswitch between connecting the first transmission input terminal to poweramplifier 11 and connecting the first transmission input terminal topower amplifier 12, according to an input transmission signal.

Switches 55 and 56 may be achieved by one double pole double throw(DPDT) switch circuit that includes two common terminals and twoselection terminals. In this case, a first transmission input terminalis connected to one of the common terminals, and a second transmissioninput terminal is connected to the other common terminal. One of theselection terminals is connected to power amplifier 11, and the otherselection terminal is connected to power amplifier 12. This connectionconfiguration allows the switch circuit to switch between connecting onecommon terminal out of the common terminals to one selection terminalout of the selection terminals and connecting the one common terminal tothe other selection terminal, and switches between connecting the othercommon terminal to the one selection terminal and connecting the othercommon terminal to the other selection terminal.

In this case, for example, a transmission signal of communication band Aor B is input through the first transmission input terminal, and atransmission signal of communication band C is input through the secondtransmission input terminal. For example, a 4G transmission signal maybe input through the first transmission input terminal, and a 5Gtransmission signal may be input through the second transmission inputterminal.

One end of transmission path AT is connected to switch 55, and the otherend of transmission path AT is connected to antenna connection terminal100. One end of transmission path BT is connected to switch 55, and theother end of transmission path BT is connected to antenna connectionterminal 100. One end of transmission path CT is connected to switch 56,and the other end of transmission path CT is connected to antennaconnection terminal 100.

In the configuration of radio frequency module 1F, switch 55, poweramplifier 11, switch 51, transmission filter 61T, matching circuit 71,switch 54, and filter 60L are included in a first transmission circuitthat transfers a transmission signal of communication band A towardantenna connection terminal 100. Filter 60L, switch 54, matching circuit71, reception filter 61R, switch 52, matching circuit 41, and low noiseamplifier 21 are included in a first reception circuit that transfers areception signal of communication band A from antenna 2 via antennaconnection terminal 100.

Switch 55, power amplifier 11, switch 51, transmission filter 62T,matching circuit 72, switch 54, and filter 60L are included in a secondtransmission circuit that transfers a transmission signal ofcommunication band B toward antenna connection terminal 100. Filter 60L,switch 54, matching circuit 72, reception filter 62R, switch 52,matching circuit 41, and low noise amplifier 21 are included in a secondreception circuit that transfers a reception signal of communicationband B from antenna 2 via antenna connection terminal 100.

Switch 56, power amplifier 12, switch 53, filter 63, matching circuit73, switch 54, and filter 60L are included in a third transmissioncircuit that transfers a transmission signal of communication band Ctoward antenna connection terminal 100. Filter 60L, switch 54, matchingcircuit 73, filter 63, switch 53, matching circuit 42, and low noiseamplifier 22 are included in a third reception circuit that transfers areception signal of communication band C from antenna 2 via antennaconnection terminal 100.

According to the above circuit configuration, radio frequency module 1Fcan carry out at least one of simultaneous transmission, simultaneousreception, or simultaneous transmission and reception of a radiofrequency signal of communication band A or B and a radio frequencysignal of communication band C.

[4. Arrangement of Circuit Elements of Radio Frequency Module 1GAccording to Variation 6]

FIG. 6A is a schematic diagram illustrating a planar configuration ofradio frequency module 1G according to Variation 6. FIG. 6B is aschematic diagram illustrating a cross-sectional configuration of radiofrequency module 1G according to Variation 6 and specifically,illustrates a cross section taken along line VIB to VIB in FIG. 6A. Notethat (a) of FIG. 6A illustrates a layout of circuit elements whenprincipal surface 91 a out of principal surfaces 91 a and 91 b onopposite sides of module board 91 is viewed from the positive z-axis. Onthe other hand, (b) of FIG. 6A is a perspective view of layout ofcircuit elements when principal surface 91 b is viewed from the positivez-axis.

Radio frequency module 1G according to Variation 6 specifically showsthe arrangement of circuit elements included in radio frequency module1F according to Variation 5.

Radio frequency module 1G according to this variation is different fromradio frequency module 1A according to the example, in the arrangementof circuit elements included in radio frequency module 1G. The followingdescription of radio frequency module 1G according to this variationfocuses on differences from radio frequency module 1A according to theexample while a description of the same points is omitted.

As illustrated in FIGS. 6A and 6B, amplification elements 11A, 11B, 12A,and 12B, interstage transformers 33 and 38, capacitors 32 and 37,duplexers 61 and 62, filter 63, matching circuits 71, 72, and 73, andswitches 54, 55, and 56 are mounted on principal surface 91 a of moduleboard 91, in radio frequency module 1G according to this variation. Onthe other hand, low noise amplifiers 21 and 22, output transformers 31and 36, matching circuits 41 and 42, switches 51, 52, and 53, anddiplexer 60 are mounted on principal surface 91 b of module board 91.

In this variation, low noise amplifiers 21 and 22 and switches 51, 52,and 53 are first circuit components, and are disposed on principalsurface 91 b. On the other hand, amplification elements 11A, 11B, 12A,and 12B are disposed on principal surface 91 a.

According to the above configuration, amplification elements 11A, 11B,12A, and 12B and the first circuit components are disposed on two sidesof module board 91 with module board 91 therebetween. Accordingly, radiofrequency module 1G can be miniaturized, as compared with aconfiguration in which amplification elements 11A, 11B, 12A, and 12B andthe first circuit components are all disposed on one side of moduleboard 91. Amplification elements 11A, 11B, 12A, and 12B and the firstcircuit components are disposed with module board 91 therebetween, sothat transmission signals output from amplification elements 11A, 11B,12A, and 12B can be prevented from being coupled with the first circuitcomponents via an electric field, a magnetic field, or anelectromagnetic field. Accordingly, small radio frequency module 1G inwhich transfer loss of the transmission signals is reduced can beprovided.

Note that amplification elements 11A, 11B, 12A, and 12B may be disposedon principal surface 91 b, and the first circuit components may bedisposed on principal surface 91 a. Also, this can miniaturize radiofrequency module 1G, and can prevent transmission signals output fromamplification elements 11A, 11B, 12A, and 12B from being coupled withthe first circuit components via an electric field, a magnetic field, oran electromagnetic field.

In radio frequency module 1G according to this variation, as illustratedin FIG. 6A, amplification elements 11A and 11B and interstagetransformer 33 may be included in one semiconductor IC 76. Further, asillustrated in FIG. 6A, amplification elements 12A and 12B andinterstage transformer 38 may be included in one semiconductor IC 77.

Accordingly, amplification elements 11A and 11B included in poweramplifier 11, and interstage transformer 33 are close to one another,and amplification elements 12A and 12B included in power amplifier 12and interstage transformer 38 are close to one another, and thus radiofrequency module 1G can be miniaturized. Further, lines that connectamplification elements 11A and 11B to interstage transformer 33, andlines that connect amplification elements 12A and 12B to interstagetransformer 38 can be shortened, and thus transfer loss of transmissionsignals can be reduced.

In radio frequency module 1G according to this variation, as illustratedin FIG. 6A, low noise amplifiers 21 and 22 and switches 52 and 53 may beincluded in one semiconductor IC 75.

Accordingly, low noise amplifiers 21 and 22 and switches 52 and 53included in reception circuits are close to one another, and thus radiofrequency module 1G can be miniaturized. Lines that connect low noiseamplifiers 21 and 22 to switches 52 and 53 can be shortened, and thustransfer loss of reception signals can be reduced.

Furthermore, matching circuit 41 connected between low noise amplifier21 and switch 52, and matching circuit 42 connected between low noiseamplifier 21 and switch 52 may be disposed on principal surface 91 b,adjacently to semiconductor IC 75.

Accordingly, low noise amplifiers 21 and 22, switches 52 and 53, andmatching circuits 41 and 42 included in reception circuits are adjacentto one another, and thus radio frequency module 1G can be furtherminiaturized. Moreover, lines that connect low noise amplifiers 21 and22 to switches 52 and 53 can be shortened, and thus transfer loss ofreception signals can be further reduced.

Note that when matching circuits 41 and 42 are disposed on principalsurface 91 b, inductors or capacitors included in matching circuits 41and 42 may be desirably integrated passive devices (IPDs) mounted on thesurface or inside of a Si substrate, for example. According to this, theheight of matching circuits 41 and 42 can be reduced.

In radio frequency module 1G according to this variation, switch 55 andsemiconductor IC 76 are adjacently disposed as illustrated in FIG. 6A.As illustrated in FIG. 6A, switch 56 and semiconductor IC 77 areadjacently disposed. In a plan view of module board 91, at least one oftransmission input terminal 111 a or 111 b may be disposed in a regionincluded in principal surface 91 b and overlapping switch 55. In a planview of module board 91, at least one of transmission input terminal 112a or 112 b may be disposed in a region included in principal surface 91b and overlapping switch 56.

Accordingly, transmission paths that connect the four transmission inputterminals to power amplifiers 11 and 12 can be shortened, and thustransfer loss of transmission signals can be reduced.

Note that a state in which “circuit element A and circuit element B areadjacently disposed” means that no other circuit element is disposedbetween circuit element A and circuit element B, in a plan view ofmodule board 91.

In radio frequency module 1G according to this variation, duplexers 61and 62 may be disposed on principal surface 91 a, and output transformer31 may be disposed on principal surface 91 b, as illustrated in FIG. 6A.At this time, it is desirable that in a plan view of module board 91,ground electrode layer 95 g and output transformer 31 at least partiallyoverlap, and ground electrode layer 95 g and at least one of duplexer 61or 62 at least partially overlap. Note that ground electrode layer 95 gis an electric conduction pattern formed on module board 91 in adirection parallel to principal surfaces 91 a and 91 b and having theground potential.

According to this, ground electrode layer 95 g is disposed betweenoutput transformer 31 and duplexers 61 and 62, a high-power transmissionsignal output from output transformer 31 and harmonics thereof can beprevented from leaking to reception paths via duplexers 61 and 62.Accordingly, deterioration of reception sensitivity can be reduced.

In a plan view of module board 91, it is desirable that duplexers 61 and62 and output transformer 31 at least partially overlap. Accordingly,transmission paths that connect duplexers 61 and 62 to outputtransformer 31 can be shortened, and thus transfer loss of transmissionsignals can be reduced.

[5. Arrangement of Circuit Elements of Radio Frequency Module 1HAccording to Variation 7]

FIG. 7A is a schematic diagram illustrating a planar configuration ofradio frequency module 1H according to Variation 7. FIG. 7B is aschematic diagram illustrating a cross-sectional configuration of radiofrequency module 1H according to Variation 7 and specifically,illustrates a cross section taken along line VIIB to VIIB in FIG. 7A.Note that (a) of FIG. 7A illustrates a layout of circuit elements whenprincipal surface 91 a out of principal surfaces 91 a and 91 b onopposite sides of module board 91 is viewed from the positive z-axis. Onthe other hand, (b) of FIG. 7A is a perspective view of layout ofcircuit elements when principal surface 91 b is viewed from the positivez-axis. Output transformers 31 and 36 formed inside of module board 91are illustrated to FIG. 7A with dashed lines.

Radio frequency module 1H according to Variation 7 specifically showsthe arrangement of circuit elements included in radio frequency module1F according to Variation 5.

Radio frequency module 1H according to this variation is different fromradio frequency module 1A according to the example, in the arrangementof circuit elements included in radio frequency module 1H. The followingdescription of radio frequency module 1H according to this variationfocuses on differences from radio frequency module 1A according to theexample while a description of the same points is omitted.

Module board 91 is a board which includes principal surface 91 a (asecond principal surface) and principal surface 91 b (a first principalsurface) on opposite sides of module board 91, and on which the abovetransmission circuits and the above reception circuits are mounted. Asmodule board 91, for example, one of an LTCC board, an HTCC board, acomponent-embedded board, a board that includes an RDL, and a printedcircuit board each having a stacked structure of a plurality ofdielectric layers is used.

As illustrated in FIGS. 7A and 7B, in radio frequency module 1Haccording to this variation, capacitors 32 and 37, duplexers 61 and 62,filter 63, matching circuits 41 and 42, and switches 51 and 54 aremounted on principal surface 91 a (a second principal surface) of moduleboard 91. On the other hand, amplification elements 11A, 11B, 12A, and12B, interstage transformers 33 and 38, low noise amplifiers 21 and 22,switches 52 and 53, and diplexer 60 are mounted on principal surface 91b (a first principal surface) of module board 91. Output transformers 31and 36 are formed inside of module board 91. Note that although notillustrated in FIG. 7A or 7B, matching circuits 71 to 73 may be mountedon any of principal surfaces 91 a and 91 b of module board 91 orprovided inside of module board 91.

In this variation, capacitors 32 and 37, duplexers 61 and 62, filter 63,matching circuits 41 and 42, and switches 51 and 54 are first circuitcomponents, and are disposed on principal surface 91 a (the secondprincipal surface). On the other hand, amplification elements 11A, 11B,12A, and 12B are disposed on principal surface 91 b (the first principalsurface).

According to the above configuration, amplification elements 11A, 11B,12A, and 12B and the first circuit components are disposed on two sidesof module board 91, with module board 91 therebetween. Accordingly,radio frequency module 1H can be miniaturized, as compared with aconfiguration in which amplification elements 11A, 11B, 12A, and 12B andthe first circuit components are all disposed on one side of moduleboard 91. Amplification elements 11A, 11B, 12A, and 12B and the firstcircuit components are disposed with module board 91 therebetween, andthus transmission signals output from amplification elements 11A, 11B,12A, and 12B can be prevented from being coupled with the first circuitcomponents via an electric field, a magnetic field, or anelectromagnetic field. Accordingly, small radio frequency module 1H inwhich transfer loss of the transmission signals is reduced can beprovided.

In radio frequency module 1H according to this variation, amplificationelements 11A and 11B and interstage transformer 33 may be included inone semiconductor IC 76, as illustrated in FIG. 7A. As illustrated inFIG. 7A, amplification elements 12A and 12B and interstage transformer38 may be included in one semiconductor IC 77.

Accordingly, interstage transformer 33 and amplification elements 11Aand 11B included in power amplifier 11 are adjacently disposed, andinterstage transformer 38 and amplification elements 12A and 12Bincluded in power amplifier 12 are adjacently disposed, and thus radiofrequency module 1H can be miniaturized. Lines that connectamplification elements 11A and 11B to interstage transformer 33, andlines that connect amplification elements 12A and 12B to interstagetransformer 38 can be shortened, transfer loss of transmission signalscan be reduced.

In radio frequency module 1H according to this variation, low noiseamplifiers 21 and 22 and switches 52 and 53 may be included in onesemiconductor IC 75, as illustrated in FIG. 7A.

Accordingly, low noise amplifiers 21 and 22 and switches 52 and 53included in reception circuits are disposed adjacently, and thus radiofrequency module 1H can be miniaturized. In addition, the lines thatconnect low noise amplifiers 21 and 22 to switches 52 and 53 can beshortened, and thus transfer loss of reception signals can be reduced.

In radio frequency module 1H according to this variation, as illustratedin FIG. 7A, switch 55 and semiconductor IC 76 are separately disposed onprincipal surfaces 91 a and 91 b, and in a plan view of module board 91,switch 55 and semiconductor IC 76 at least partially overlap.Accordingly, transmission paths that connect transmission inputterminals 111 a and 111 b to power amplifier 11 can be shortened, andthus transfer loss of transmission signals can be reduced.

As illustrated in FIG. 7A, switch 56 and semiconductor IC 77 areseparately disposed on principal surfaces 91 a and 91 b, and in a planview of module board 91, switch 56 and semiconductor IC 77 may at leastpartially overlap. Accordingly, transmission paths that connecttransmission input terminals 112 a and 112 b to power amplifier 12 canbe shortened, and thus transfer loss of transmission signals can bereduced.

In radio frequency module 1H according to this variation, as illustratedin FIG. 7A, in a plan view of module board 91, it is desirable thatamplification elements 11A and 11B and output transformer 31 do notoverlap, and amplification elements 12A and 12B and output transformer36 do not overlap.

Accordingly, amplification elements 11A and 11B and secondary coil 31 bof output transformer 31 can be prevented from being unnecessarilycoupled with one another via a magnetic field or an electromagneticfield, and amplification elements 12A and 12B and secondary coil 36 b ofoutput transformer 36 can be prevented from being unnecessarily coupledwith one another via a magnetic field or an electromagnetic field.Accordingly, this can reduce an increase in transfer loss and anincrease in spurious waves due to a decrease in the degree of impedancematching of power amplifiers 11 and 12.

As illustrated in FIGS. 7A and 7B, in a plan view of module board 91, nocircuit component is desirably disposed in regions included in principalsurface 91 a and principal surface 91 b and overlapping a formationregion in which output transformers 31 and 36 are formed. Accordingly,the fall of amplification performance of power amplifiers 11 and 12 canbe reduced.

In radio frequency module 1H according to this variation, a plurality ofexternal-connection terminals 150 are disposed on principal surface 91 b(a first principal surface) of module board 91. External-connectionterminals 150 used as ground electrodes are disposed between low noiseamplifiers 21 and 22 that greatly affect reception sensitivity ofreception circuits and power amplifiers 11 and 12, and thusdeterioration of reception sensitivity of the reception circuits can bereduced.

In radio frequency module 1H according to this variation, as illustratedin FIG. 7A, duplexers 61 and 62 are disposed on principal surface 91 a,and output transformer 31 may be disposed on principal surface 91 b. Atthis time, in a plan view of module board 91, it is desirable thatground electrode layer 95 g and output transformer 31 at least partiallyoverlap, and ground electrode layer 95 g and at least one of duplexer 61or 62 at least partially overlap.

According to this, ground electrode layer 95 g is disposed betweenoutput transformer 31 and duplexers 61 and 62, and thus a high-powertransmission signal output from output transformer 31 and harmonicsthereof can be prevented from leaking to reception paths via duplexers61 and 62. Consequently, deterioration of reception sensitivity can bereduced.

In radio frequency module 1H according to this variation, as illustratedin FIGS. 7A and 7B, semiconductor IC 76, output transformer 31, switch51, duplexers 61 and 62, and switch 54 are disposed in the order fromthe left end of module board 91 (the end of the negative x-axis in FIGS.7A and 7B) to the right end (the end of the positive x-axis in FIGS. 7Aand 7B).

According to this, transmission signals of communication bands A and Bcan be transferred in radio frequency module 1H, from the left end ofmodule board 91 to the right end in substantially one direction, and canbe prevented from returning in the opposite direction. Accordingly, thetransfer paths of transmission signals of communication bands A and Bare shortened, and thus transfer loss of the transmission signals can bereduced.

[6. Advantageous Effects and Others]

As described above, radio frequency module 1 according to the presentembodiment includes: module board 91 that includes principal surface 91a and principal surface 91 b on opposite sides of module board 91; poweramplifier 11; and a first circuit component. Power amplifier 11includes: amplifying element 11A; amplifying element 11B; and outputtransformer 31 that includes primary coil 31 a and secondary coil 31 b.An end of primary coil 31 a is connected to an output terminal ofamplifying element 11A, and another end of primary coil 31 a isconnected to an output terminal of amplifying element 11B. An end ofsecondary coil 31 b is connected to output terminal 116 of poweramplifier 11. Amplifying element 11A and amplifying element 11B aredisposed on principal surface 91 a. The first circuit component isdisposed on principal surface 91 b.

Accordingly, amplifying elements 11A and 11B and the first circuitcomponent are disposed on two sides of module board 91 with module board91 therebetween. Accordingly, radio frequency module 1 can beminiaturized, as compared with a configuration in which amplifyingelements 11A and 11B and the first circuit component are all disposed onone side of module board 91. Amplifying elements 11A and 11B and thefirst circuit component are disposed with module board 91 therebetween,so that transmission signals output from amplifying elements 11A and 11Bcan be prevented from being coupled with the first circuit component viaan electric field, a magnetic field, or an electromagnetic field.Accordingly, small radio frequency module 1 in which transfer loss ofthe transmission signal is decreased can be provided.

Radio frequency module 1 further includes: transmission input terminal111; reception output terminal 121; and antenna connection terminal 100.The first circuit component is a circuit component connected toreception path AR or BR connected to reception output terminal 121 andantenna connection terminal 100, and in a plan view of module board 91,output transformer 31 and the first circuit component disposed onprincipal surface 91 b may not overlap.

Accordingly, transmission signals that are output from amplifyingelements 11A and 11B and transferred in output transformer 31 can beprevented from being coupled with one or more first circuit componentsdisposed on one or both of reception paths AR and BR via a magneticfield or an electromagnetic field. Accordingly, isolation of poweramplifier 11 from the reception circuits improves, and thus this caneffectively reduce a decrease in reception sensitivity caused by thetransmission signals, harmonics, and spurious waves due tointermodulation distortion sneaking into at least one of reception pathAR or BR.

In radio frequency module 1, the first circuit component may be lownoise amplifier 21.

Accordingly, transmission signals that are output from amplifyingelements 11A and 11B and transferred in output transformer 31 can beprevented from being coupled with low noise amplifier 21 via a magneticfield or an electromagnetic field. Accordingly, isolation of poweramplifier 11 from low noise amplifier 21 improves, and thus this canfurther reduce a decrease in reception sensitivity caused by thetransmission signals, harmonics, and spurious waves due tointermodulation distortion sneaking into the reception path.

In radio frequency module 1, in a plan view of module board 91,desirably, amplifying element 11A and output transformer 31 do notoverlap, and amplifying element 11B and output transformer 31 do notoverlap.

Accordingly, amplifying elements 11A and 11B and secondary coil 31 b canbe prevented from being unnecessarily coupled with each other via amagnetic field or an electromagnetic field. Accordingly, an increase intransfer loss and an increase in unnecessary waves due to a decrease inthe degree of impedance matching inside of power amplifier 11 can bereduced.

In radio frequency module 1, desirably, module board 91 includes groundelectrode layer 95 g formed in a direction parallel to principal surface91 a and principal surface 91 b, and in a plan view of module board 91,ground electrode layer 95 g is not formed in a region overlapping outputtransformer 31.

According to this, it can be ensured that output transformer 31 andground electrode 95 g are widely spaced apart from each other, and thustransfer loss of a transmission signal transferred in power amplifier 11can be decreased.

In radio frequency module 1, output transformer 31 may not be formedinside of module board 91, between principal surface 91 a and principalsurface 91 b.

According to this, it is not necessary to dispose output transformer 31on principal surface 91 a or principal surface 91 b, and thus the areafor radio frequency module 1 can be reduced.

In radio frequency module 1, in a plan view of module board 91,desirably, no circuit component is disposed in a region included inprincipal surface 91 a and overlapping output transformer 31, or in aregion included in principal surface 91 b and overlapping outputtransformer 31.

According to this, no circuit component is disposed in the regionincluded in principal surface 91 a or the region included in principalsurface 91 b, and thus a decrease in the Q factor of the inductor ofoutput transformer 31 can be reduced.

In radio frequency module 1A/1C, output transformer 31 may be formedinside of module board 91 between principal surface 91 a and principalsurface 91 b, output transformer 31 being offset toward one of principalsurface 91 a and principal surface 91 b, and in a plan view of moduleboard 91, no circuit component may be disposed in a region included inthe one of principal surface 91 a and principal surface 91 b, andoverlapping output transformer 31, and a circuit component may bedisposed in a region included in the other of principal surface 91 a andprincipal surface 91 b, and overlapping output transformer 31.

Also in this case, no circuit component is disposed in the regionincluded in principal surface 91 a or 91 b closer to output transformer31, and thus a decrease in the Q factor of the inductor of outputtransformer 31 can be reduced.

In radio frequency module 1E, desirably, output transformer 31 isdisposed on principal surface 91 a, and in a plan view of module board91, no circuit component is disposed in a region included in principalsurface 91 b and overlapping output transformer 31.

According to this, no circuit component is disposed in the region inprincipal surface 91 b, and thus a decrease in the Q factor of theinductor of output transformer 31 can be reduced.

In radio frequency module 1D, desirably, output transformer 31 isdisposed on principal surface 91 b, and in a plan view of module board91, no circuit component is disposed in a region included in principalsurface 91 a and overlapping output transformer 31.

According to this, no circuit component is disposed in the region inprincipal surface 91 a, and thus a decrease in the Q factor of theinductor of output transformer 31 can be reduced.

Radio frequency module 1G may further include: duplexer 61 configured topass a transmission signal of communication band A and a receptionsignal of communication band A. Duplexer 61 may include: transmissionfilter 61T that includes an input end connected to output terminal 116of power amplifier 11; and reception filter 61R that includes an inputend connected to an output end of transmission filter 61T. Duplexer 61may be disposed on principal surface 91 a. Module board 91 may includeground electrode layer 95 g formed in a direction parallel to principalsurface 91 a and principal surface 91 b. In a plan view of module board91, ground electrode layer 95 g and output transformer 31 may at leastpartially overlap, and ground electrode layer 95 g and duplexer 61 mayat least partially overlap.

According to this, ground layer 95 g is disposed between duplexer 61 andoutput transformer 31, and thus a high-power transmission signal outputfrom output transformer 31 and harmonics thereof can be prevented fromleaking to a reception path via duplexer 61. Consequently, deteriorationof reception sensitivity can be reduced.

In radio frequency module 1G, in a plan view of module board 91, outputtransformer 31 and duplexer 61 may at least partially overlap.

Accordingly, a transmission path that connects duplexer 61 and outputtransformer 31 can be shortened, and thus transfer loss of atransmission signal can be decreased.

In radio frequency module 1, external-connection terminal 150 may bedisposed on principal surface 91 b.

According to this, power amplifier 11 is mounted on principal surface 91a, and power amplifier 11 and external-connection terminal 150 can beconnected via a penetrating electrode that passes through module board91 between principal surface 91 a and principal surfaces 91 b.Accordingly, as heat dissipation paths for transmission power amplifier11, a heat dissipation path extending along only a planar line patternin the xy plane direction and having high heat resistance can beexcluded from lines on and in module board 91. Thus, miniaturized radiofrequency module 1 having improved heat dissipation from transmissionpower amplifier 11 to the motherboard can be provided.

In radio frequency module 1H, external-connection terminal 150 may bedisposed on principal surface 91 b.

According to this, amplifying elements 11A, 11B, 12A, and 12B and thefirst circuit component are disposed on two sides of module board 91,with module board 91 therebetween. Accordingly, radio frequency module1H can be miniaturized, as compared with a configuration in whichamplifying elements 11A, 11B, 12A, and 12B and the first circuitcomponent are all disposed on one side of module board 91.

A radio frequency module according to another aspect may include: moduleboard 91 that includes principal surface 91 a and principal surface 91 bon opposite sides of module board 91; and power amplifier 11. Poweramplifier 11 may include: amplifying element 11A; amplifying element11B; and output transformer 31 that includes primary coil 31 a andsecondary coil 31 b. An end of primary coil 31 a may be connected to anoutput terminal of amplifying element 11A, and another end of primarycoil 31 a may be connected to an output terminal of amplifying element11B. An end of secondary coil 31 b may be connected to output terminal116 of power amplifier 11. Amplifying element 11A may be disposed onprincipal surface 91 a, and amplifying element 11B may be disposed onprincipal surface 91 b.

According to this, amplifying element 11A and amplifying element 11B aredisposed on two sides of module board 91 with module board 91therebetween. Accordingly, the radio frequency module can beminiaturized, as compared with a configuration in which both amplifyingelements 11A and 11B are disposed on one side of module board 91.Further, amplifying element 11A and amplifying element 11B are disposedwith module board 91 therebetween, and thus a balanced transmissionsignal output from amplifying element 11A and a balanced transmissionsignal output from amplifying element 11B can be prevented from beingcoupled with each other via an electric field, a magnetic field, or anelectromagnetic field before the signals are input to output transformer31. Accordingly, a small radio frequency module in which transfer lossof the transmission signals is decreased can be provided.

Communication device 5 includes: antenna 2; RFIC 3 configured to processa radio frequency signal to be transmitted by antenna 2 and a radiofrequency signal received by antenna 2; and radio frequency module 1configured to transfer the radio frequency signals between antenna 2 andRFIC 3.

Accordingly, small communication device 5 that includes a differenceamplifying type power amplifier can be provided.

Other Embodiments

The above has described the radio frequency module and the communicationdevice according to the present disclosure, using the embodiment and theexamples, yet the radio frequency module and the communication deviceaccording to the present disclosure are not limited to the embodimentand the examples. The present disclosure also encompasses anotherembodiment achieved by combining arbitrary elements in the embodimentand the examples, variations as a result of applying variousmodifications that may be conceived by those skilled in the art to theembodiment and the examples without departing from the scope of thepresent disclosure, and various apparatuses that include the radiofrequency module and the communication device according to the presentdisclosure.

For example, in the radio frequency modules and the communicationdevices according to the embodiment and the examples thereof, anothercircuit element and another line, for instance, may be disposed betweencircuit elements and paths that connect signal paths illustrated in thedrawings.

Although only some exemplary embodiments of the present disclosure havebeen described in detail above, those skilled in the art will readilyappreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of the present disclosure. Accordingly, all suchmodifications are intended to be included within the scope of thepresent disclosure.

INDUSTRIAL APPLICABILITY

The present disclosure can be widely used in communication apparatusessuch as mobile phones, as a radio frequency module disposed in a frontend portion that supports multiband technology.

The invention claimed is:
 1. A radio frequency module, comprising: amodule board that includes a first principal surface and a secondprincipal surface on opposite sides of the module board; a poweramplifier configured to amplify a transmission signal; and a firstcircuit component, wherein the power amplifier includes: a firstamplifying circuit element; a second amplifying circuit element; and anoutput transformer that includes a first coil and a second coil, an endof the first coil is connected to an output terminal of the firstamplifying circuit element, another end of the first coil is connectedto an output terminal of the second amplifying circuit element, an endof the second coil is connected to an output terminal of the poweramplifier, the first amplifying circuit element and the secondamplifying circuit element are disposed on the first principal surface,and the first circuit component is disposed on the second principalsurface.
 2. The radio frequency module according to claim 1, furthercomprising: a transmission input terminal; a reception output terminal;and an input/output terminal, wherein the first circuit component is acircuit component connected to a reception path connected to thereception output terminal and the input/output terminal, and in a planview of the module board, the output transformer and the first circuitcomponent disposed on the second principal surface do not overlap. 3.The radio frequency module according to claim 2, wherein the firstcircuit component is a reception low noise amplifier.
 4. The radiofrequency module according to claim 1, wherein in a plan view of themodule board, the first amplifying circuit element and the outputtransformer do not overlap, and the second amplifying circuit elementand the output transformer do not overlap.
 5. The radio frequency moduleaccording to claim 1, wherein the module board includes a groundelectrode layer formed in a direction parallel to the first principalsurface and the second principal surface, and in a plan view of themodule board, the ground electrode layer is not formed in a regionoverlapping the output transformer.
 6. The radio frequency moduleaccording to claim 1, wherein the output transformer is disposed insideof the module board, between the first principal surface and the secondprincipal surface.
 7. The radio frequency module according to claim 6,wherein in a plan view of the module board, no circuit component isdisposed in a region included in the first principal surface andoverlapping the output transformer, or in a region included in thesecond principal surface and overlapping the output transformer.
 8. Theradio frequency module according to claim 6, wherein the outputtransformer is disposed inside of the module board between the firstprincipal surface and the second principal surface, the outputtransformer being offset toward one of the first principal surface andthe second principal surface, and in a plan view of the module board, nocircuit component is disposed in a region included in the one of thefirst principal surface and the second principal surface, andoverlapping the output transformer, and a circuit component is disposedin a region included in an other of the first principal surface and thesecond principal surface, and overlapping the output transformer.
 9. Theradio frequency module according to claim 1, wherein the outputtransformer is disposed on the first principal surface, and in a planview of the module board, no circuit component is disposed in a regionincluded in the second principal surface and overlapping the outputtransformer.
 10. The radio frequency module according to claim 1,wherein the output transformer is disposed on the second principalsurface, and in a plan view of the module board, no circuit component isdisposed in a region included in the first principal surface andoverlapping the output transformer.
 11. The radio frequency moduleaccording to claim 10, further comprising: a duplexer configured to passa transmission signal of the first communication band and a receptionsignal of the first communication band, wherein the duplexer includes: atransmission filter that includes an input end connected to an outputterminal of the power amplifier; and a reception filter that includes aninput end connected to an output end of the transmission filter, theduplexer is disposed on the first principal surface, the module boardincludes a ground electrode layer formed in a direction parallel to thefirst principal surface and the second principal surface, and in a planview of the module board, the ground electrode layer and the outputtransformer at least partially overlap, and the ground electrode layerand the duplexer at least partially overlap.
 12. The radio frequencymodule according to claim 11, wherein in a plan view of the moduleboard, the output transformer and the duplexer at least partiallyoverlap.
 13. The radio frequency module according to claim 1, wherein anexternal-connection terminal is disposed on the second principalsurface.
 14. The radio frequency module according to claim 1, wherein anexternal-connection terminal is disposed on the first principal surface.15. A radio frequency module, comprising: a module board that includes afirst principal surface and a second principal surface on opposite sidesof the module board; and a power amplifier configured to amplify atransmission signal, wherein the power amplifier includes: a firstamplifying circuit element; a second amplifying circuit element; and anoutput transformer that includes a first coil and a second coil, an endof the first coil is connected to an output terminal of the firstamplifying circuit element, another end of the first coil is connectedto an output terminal of the second amplifying circuit element, an endof the second coil is connected to an output terminal of the poweramplifier, the first amplifying circuit element is disposed on the firstprincipal surface, and the second amplifying circuit element is disposedon the second principal surface.
 16. A communication device, comprising:an antenna; a radio frequency (RF) signal processing circuit configuredto process a radio frequency signal to be transmitted by the antenna anda radio frequency signal received by the antenna; and the radiofrequency module according to claim 15 configured to transfer the radiofrequency signals between the antenna and the RF signal processingcircuit.
 17. A communication device, comprising: an antenna; a radiofrequency (RF) signal processing circuit configured to process a radiofrequency signal to be transmitted by the antenna and a radio frequencysignal received by the antenna; and a radio frequency module configuredto transfer the radio frequency signals between the antenna and the RFsignal processing circuit, the radio frequency module including a moduleboard that includes a first principal surface and a second principalsurface on opposite sides of the module board, a power amplifierconfigured to amplify a transmission signal, and a first circuitcomponent, wherein the power amplifier includes a first amplifyingcircuit element, a second amplifying circuit element and an outputtransformer that includes a first coil and a second coil, an end of thefirst coil is connected to an output terminal of the first amplifyingcircuit element, another end of the first coil is connected to an outputterminal of the second amplifying circuit element, an end of the secondcoil is connected to an output terminal of the power amplifier, thefirst amplifying circuit element and the second amplifying circuitelement are disposed on the first principal surface, and the firstcircuit component is disposed on the second principal surface.